The Clinical Core will enroll and follow study participants with genital HSV-2 as well as genital HSV-1 . Specific Aims of the Clinical Core is 1) to recruit, screen and enroll into research protocols subjects from defined populations; 2) to follow participants prospectively on studies, maintaining close adherence to study procedures, and 3) to obtain clinical specimens required for virologic and immunologic laboratory investigations detailed in Projects 1 and 3, using both standard and specialized techniques. In particular, the efforts will focus on enrolling a) participants with genital HSV-2 to address the specific aims of Project 1, including both HIV negative, HIV positive, pregnant women, and those with iatrogenic immunosuppression, and c) participants with genital HSV-2 to address the specific aims of Project 3. The core will also recruit and follow participants enrolled into studies examining the effect of antiviral therapy on HSV reactivation both in HIV negative and HIV positive persons. For project 2, the Clinical Core will be a site where the neonates who are receiving oral acyclovir will be evaluated and monitored. The Core is located at the University of Washington Virology Research Clinic (VRC). The VRC was founded in 1974 as a center for studies of natural history and therapeutics of HSV infections. The clinic has followed >1000 persons with first episode of genital herpes and >3400 persons with recurrent HSV-2 infection. The clinic has pioneered the use of daily genital swabs to evaluate the reactivation of HSV on mucosa, and to characterize the mucosal interactions between HSV and HIV. In the last decade, we have moved to using HSV DNA PCR for evaluation of viral shedding; using this method, we have been able to demonstrate viral shedding in almost all HSV seropositive persons. Other procedures that have become standard in our clinic include biopsies of genital lesions and normal skin, rectal and cervical biopsies, UV light induction of genital herpes recurrences, and leukapheresis for detailed virologic and immunologic studies of host-virus interactions. Both host and viral DNA of participants in the detailed virologic and immunologic studies are stored for future investigations of genetic determinants of HSV susceptibility, resistance and disease severity as well as viral sequencing work. The Clinical Core is dedicated to recruiting, screening, enrolling and following persons who have HSV infections into a variety of studies. Most persons are followed over time, often with daily swabs to measure the frequency of viral shedding on the skin and mucosa. In addition, a variety of specialized techniques are available.